Question: $\left[\begin{array} {ccc} 0& 5& 0& 6\\ -4& 1& 1& -6\\ 4& -7& -5& 5 \end{array}\right]$ What are the dimensions of the matrix?
Answer: The first dimension is the number of rows in the matrix. There are $3$ rows. The second dimension is the number of columns in the matrix. There are $4$ columns. In conclusion, the dimensions of the matrix are $3\times 4$.